function eta0_cal = cal_fun_find_helper_pscc(phi,disc_target,al,d,del,g)
%calibration file finding eta0 targeting sale discount, given phi

options = optimoptions('fsolve','TolFun',1e-9,'TolX',1e-9,'StepTolerance',1e-9,'Display','final');

disc_fun=@(eta0_temp) cal_fun_disc_pscc(eta0_temp,phi,al,d,del,g)-disc_target;
eta0_cal=fsolve(disc_fun,.5,options);
end